1. Field of the Invention
The present invention relates to novel quinazoline derivatives and more particularly to such quinazolinone derivatives having a pyrazole ring fused to the benzo moiety of the quinazolinone.
2Description of the Prior Art
Pyrazolo [3,4-d]-pyrimidine-4-one having the formula ##STR2## is well known under the generic name Allopurinol. Since its first preparation more than two decades ago (cf. R. K. Robbins, J. Am. Chem. Soc. 78, 1956, 784) it has been used for therapeutical purposes as an inhibitor of xanthine oxidase and for its controlling effect upon the concentration of uric acid in human blood; it is probably the most widely used drug for the treatment of gout and similar metabolic diseases of the human body. Because of the relatively low solubility of allopurinol and the need to use it at a relatively high dosage level, there is a substantial need to find new compounds that have a sufficient structural similarity with allopurinol to retain or increase its beneficial effects and/or to provide such allopurinol-related substances that have generally more favorable physiological and therapeutic effects than allopurinol.
Accordingly, it is a main object of this invention to provide for novel compounds that include the effective moieties of allopurinol in a modified structural arrangement.
Another object is a method of producing novel compounds that include the allopurinol moieties.
A further object is to provide for allopurinol-related compounds for therapeutic use instead of, or in combination with, allopurinol.
Other objects will become apparent as the specification proceeds.